Several occupations require the use of a portable lantern. However, in a wide variety of hazardous environments conventional lanterns are unusable. The Occupational Safety and Health Administration (OSHA) has classified a number of hazardous work environments where special precaution must be taken to provide workers with safe working conditions. The most extreme work environment is classified as Class I, Division 1. A Class I, Division I work environment is a location in which: (a) hazardous concentrations of flammable gases or vapors may exist under normal operating conditions; or (b) hazardous concentrations of such gases or vapors may exist frequently because of repair or maintenance operations or because of leakage; or (c) breakdown or faulty operation of equipment or processes might release hazardous concentrations of flammable gases or vapors, and might also cause simultaneous failure of electric equipment.
Examples of work locations where Class I, Division I classifications are typically assigned include: locations where volatile flammable liquids or liquefied flammable gases are transferred from one container to another; interiors of spray booths and areas in the vicinity of spraying and painting operations where volatile flammable solvents are used; locations containing open tanks or vats of volatile flammable liquids; drying rooms or compartments for the evaporation of flammable solvents; locations containing fat and oil extraction equipment using volatile flammable solvents; portions of cleaning and dyeing plants where flammable liquids are used; gas generator rooms and other portions of gas manufacturing plants where flammable gas may escape; inadequately ventilated pump rooms for flammable gas or for volatile flammable liquids; the interiors of refrigerators and freezers in which volatile flammable materials are stored in open, lightly stoppered, or easily ruptured containers; and all other locations where ignitable concentrations of flammable vapors or gases are likely to occur in the course of normal operations.
Given the high volatility present in these types of working environments, conventional lanterns cannot be safely used since their electrical connections to batteries, hot filaments, exposed metal connections and unsealed switches could cause sparks. Thus, a need exists for a rechargeable portable lantern which can operate in such dangerous environments.